Low
Frequency Section
The 300 mm (12 in ) high pressure die cast bass driver is
loaded into a 45 liter vented box incorporating EAW's
exclusive bi-frequency tuning system. This technique makes
use of two vents tuned to different frequencies, lowering the
low frequency limit of the system. This is accomplished
without response ripples normally associated with super low
tunings. The result is strong response down to 50 Hz,
without external equalization. The bi-frequency tuning
system also reduces driver excursion at low frequencies and
distortion, resulting in greater bass definition and more
realism in the sound.
Crossover
Design & Construction
The crossover network is the heart of any system and the
FR122's crossover is the most sophisticated available in any
compact pro system. Crossover development at EAW is a
long and painstaking process. Paramet ers are mathematically
calculated and continuously adjusted during extensive
listening and precision acoustic measurement evaluations.
The final design is then built into a run of systems, each one
tested for variations. The design is then modified to
compensate for these variations. At each step in this process,
the filters are optimized to provide maximal electrical
damping and minimum phase response while providing a
smooth transition between drivers. The resulting crossover is
a third order design with nonsymmetrical slopes for
crossover equalization.
To guarantee that production crossovers achieve their design
specifications, we individually test each crossover
component
and
the
final product to be within 3% of the
original design values. This intensive effort results in the
elimination of crossover induced distortion, typically the
highest source of distortion in
compact
systems.
Architect's and Engineer's
Specifications
The loudspeaker system shall be of the two -way type,
incorporating one 12-inch low frequency loudspeaker in a
vented direct radiator enclosure and a 2-inch hard dome high
frequency driver. The system shall meet the following
performance criteria: Frequency range: 50 to 22kHz;
Pressure sensitivity: 99 dB SPL; Power Handling: 300 watts
in accordance with AES standard specification; Horizontal
coverage: 130 degrees between -6 dB points. The high
frequency driver shall have fero-fluid in the voice coil gap.
The crossover shall be a third order design incorporating
asymmetrical slopes providin g driver equalization.
Architect's & Engineer's
Specifications
Cont.
The cabinet shall be constructed of void-free
crossgrain-laminated birch plywood and coated with
catalyzed polyurethane finish. All the drivers shall be
protected with a perforated steel grill coated in vinyl.
The loudspeaker system shall be the Eastern Acoustic
Works Forsythe Series model FRI 22.
Specifications
MODEL:
FR122
Frequency Response
+- 3 dB:
50 to 20,000 Hz
- 10 dB:
40 to 22,000 Hz
Axial Sensitivity:
99 dB, SPL
Half Space Efficiency:
2.3%
Power Handling
Sine Wave:
150 watts
AES Standard:
300 watts
Nominal Impedance:
8 ohms
Coverage Angles
Horizontal:
150 degrees
Vertical:
100 degrees
Maximum SPL:
121 dB, SPL
Maximum Acoustic Output:
9 acoustic watts
Transducer Complement
Low Frequency:
RCF PRO L12/565 300mm Cone
High Frequency:
RCF TW 116 52mm Hard Dome
CrossoverData:
Type:
Third Order Equalized
Slope:
18 dB per octave
Frequency:
2800 Hz
Enclosure Type:
Vented
Enclosure Volume:
45 liters (1.6 ft3)
Construction:
Cross-Grain - Laminated Birch
Finish:
Catalyzed Polyurethane
Dimensions:
24" H x 15"W x 12.5" D
Weight:
24 Kg (53 lbs)
